GB2027546A - Fibre optic tap - Google Patents
Fibre optic tap Download PDFInfo
- Publication number
- GB2027546A GB2027546A GB7832525A GB7832525A GB2027546A GB 2027546 A GB2027546 A GB 2027546A GB 7832525 A GB7832525 A GB 7832525A GB 7832525 A GB7832525 A GB 7832525A GB 2027546 A GB2027546 A GB 2027546A
- Authority
- GB
- United Kingdom
- Prior art keywords
- fibre
- rod
- mirror
- arrangement
- light
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 239000000835 fiber Substances 0.000 title claims abstract description 32
- 239000013307 optical fiber Substances 0.000 claims abstract description 21
- 230000005540 biological transmission Effects 0.000 claims abstract description 5
- 238000010079 rubber tapping Methods 0.000 claims description 11
- 230000006872 improvement Effects 0.000 claims description 4
- 230000003287 optical effect Effects 0.000 claims description 4
- 230000009471 action Effects 0.000 claims description 2
- 238000000576 coating method Methods 0.000 claims description 2
- 230000008878 coupling Effects 0.000 claims description 2
- 238000010168 coupling process Methods 0.000 claims description 2
- 238000005859 coupling reaction Methods 0.000 claims description 2
- 238000001514 detection method Methods 0.000 claims description 2
- 238000010586 diagram Methods 0.000 claims description 2
- 230000001939 inductive effect Effects 0.000 claims description 2
- 238000003780 insertion Methods 0.000 claims description 2
- 230000037431 insertion Effects 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 claims description 2
- 238000000034 method Methods 0.000 claims description 2
- 230000008569 process Effects 0.000 claims description 2
- 230000000644 propagated effect Effects 0.000 claims description 2
- 239000000126 substance Substances 0.000 claims description 2
- 239000012780 transparent material Substances 0.000 claims 2
- 239000004020 conductor Substances 0.000 abstract 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/26—Optical coupling means
- G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
- G02B6/2804—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals forming multipart couplers without wavelength selective elements, e.g. "T" couplers, star couplers
- G02B6/2817—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals forming multipart couplers without wavelength selective elements, e.g. "T" couplers, star couplers using reflective elements to split or combine optical signals
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Optical Couplings Of Light Guides (AREA)
- Optical Communication System (AREA)
Abstract
To provide a tap to an optic fibre light conductor, a graded-index rod a half-wavelength (or an odd number of half-wavelengths) long is used with an angled mirror surface half-way along its length. Two fibres meet opposite ends of the rod, and the output due to the mirror, which is of the partially- reflective type, provides the tapped output. The reflected output thus produced is aimed at a photo-diode or, via a lens, at another optical fibre. This gives a simple and economical tap, suitable especially for use in data transmission systems.
Description
SPECIFICATION
Improvements in or relating to fibre optic devices
This invention relates to a tapping arrangement for an optical fibre cable.
In an optical fibre communications system it is frequently required to be abie to tap off part of the light in transit along the fibre. One circumstance in which this is needed is in a closed-loop communications system where tapping off is needed at each of the stations on the system. Hitherto tapping arrangements for these and other purposes have been complex and/or loss-inducing and this invention has as its object the provision of such arrangements in which the above-mentioned disadvantages are minimised.
According to the present invention there is provided an optical fibre tapping arrang.ment which includes a graded index rod whose length is an integral number of half-wavelengths long to one end of which may be coupled an input ootical fibre or a light source and to the other end cf which there may be coupled an output optical fibre, s partiallyreflecting mirror set substantially c t 45" to the axis of the rod, said mirror being an odd number of quarter-wavelengths from the input fibre or light source, and an output from the sice of the arrangement, light reflected by said mirror leaving the arrangement via said side output
Embodiments of the invention Nil now be described with reference to the accompanying drawings, in which
Figure 1 is a schematic diagram of a first embodiment of the invention.
Figure 2 illustrates one stage in the manufacture of a device such as shown in Figure 1.
Figure 3 shows a usefui improvement to the device of Figure 1.
Figure 4 and 5 show schematicaliy further embodiments of the invention.
In the arrangement of Figure 1, an input fibre 1, or a light source such as a light-emitting diode or a laser, is coupled to an output fibre 2 via a graded index rod 3 whose length is halfthewaveplength of the light being propagated from the fibre or source 1 to the fibre 2. Midway along the rod 3 there is a partially-reflecting mirror 4 set, as shown, at 45" to the axis of the rod.
Light reaching the rod 3 from the fibre 1 or source is focussed for onward transmission via the fibre 2 by the rod 3, which acts as a lens. Partial reflection in the region of the collimated, expanded, beam by the mirror 4 directs a controlled portion of the beam onto a receiver indicated at 5. The controi of the portion of the light which is thus reflected is by the extent and nature of the reflecting surface which forms the mirror.
The receiver is either a large-area photo-diode, or a lens focussing the diverted light onto a small-area photo-diode or an output fibre. The large-area photo-diode is the preferred form of receiver as this makes the arrangement relatively simple.
The device can be constructed from graded index fibre rod, e.g. 1 mm diameter so-called giant fibre drawn from a chemical vapour deposited preform, which is ground to the shape shown in Figure 2. That is, two rod sections are made each with one end normal to the axis and the other end at 45" thereto.
The sloping end faces are then provided with suitable part-reflective optical coatings, and assembled together to form a cylinder such as shown in
Figure 1.
To improve the optical coupling from the mirror to the receiver, a flat may be ground on the side of the graded-index lens assembly, as shown at 10, Figure 3.
Alignment of a graded index rod such as described above with respect to a precision bore tube or other alignment guide allows standard jewelled optical fibre terminating ferrules to be coupled to the device. Thus Figure 4 shows a precision tube 12, within which there are a graded index rod 13 and two ferrules 14 and 15 each of which terminates an optical fibre.
Another arrangement is shown in Figure 5, where we see centring using a tube 17 collapsed by the action of heat onto a graded index rod. This allows precise "spliced-in" connection to the fibres, relying for centring on the symmetry of the collapsing process.
Arrangements such as described above have a number of advantages:
(a) Simplicity, especially when used with large area, e.g. 1 mm square, photodiodes. The device is relatively cheap to make and is especially simple to install for those appiications where the light to be tapped off can go straight to a detector.
(bl They are more efficient in principle than waveguide Y-junctions or the like, when the detector's area can be relatively iarge without significant penalty, and aiso when the fibres are of unknown size, i.e. the device is not custom-designed for a particular fibre.
(c) Fairly low insertion loss is attainable, which is important for ring-type applications where a signai may suffer due to loss of many devices in series.
(d) It can couple uniformly from all modes, i.e. it need not be mode-sensitive.
A variant on the arrangements described herein would be for the mirror to reflect fully over part of its area and not over the rest: this would select ranges of output angles for onward transmission and others for detection.
In the arrangements described herein the graded index rod lens is in fact one half wavelength long, but its length can be multiples of this as long as the mirror is an integral number (including one) of quarter wavelengths from one end.
1. An optical fibre tapping arrangement, which includes a graded index rod whose length is an integral number of half-wavelengths long to one end of which may be coupled an input optical fibre or a light source and to the other end of which there may be coupled an output optical fibre. a partiallyreflecting mirror set substantiaily at 45" to the axis of the rod, said mirror being an odd number of
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (8)
1. An optical fibre tapping arrangement, which includes a graded index rod whose length is an integral number of half-wavelengths long to one end of which may be coupled an input optical fibre or a light source and to the other end of which there may be coupled an output optical fibre. a partiallyreflecting mirror set substantiaily at 45" to the axis of the rod, said mirror being an odd number of quarter-wavelengths from the input fibre or light source, and an output from the side of the arrangement, light reflected by said mirror leaving the arrangement via said side output.
2. An arrangement as claimed in claim 1, and in which said rod is formed from two separate portions each of which has one of its end faces at 45" to the axis of the rod, the two end faces being placed one against each other to produce a cylinder.
3. An arrangement as claimed in claim 1 or 2, and in which the rod has a flat machined on its surface at the area via which light reflected by said mirror leaves the rod.
4. An arrangement as claimed in claim 1, 2 or 3, and in which the rod is centrally located in a precision-bore tube whose length is such that it can receive a ferrule-ended fibre in each of its ends, said tube being of transparent material.
5. An arrangement as claimed in claim 1, 2 and 3, and in which the rod is centrally located in a tube of a transparent material which is collapsed onto the rod.
6. An arrangement as claimed in claim 1, 2, 3, 4 or 5, and in which the light reflected by said mirror is directed on to a photo-diode.
7. An arrangement as claimed in claim 1, 2,3,4 or 5, and in which the light reflected by said mirror is directed by a lens onto an optical fibre.
8. An optical fibre tapping arrangement, substantially as described with reference to Figure 1, 2, 3,4 or 5 of the accompanying cjraw;ngs.
Priority Applications (7)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB7832525A GB2027546A (en) | 1978-08-08 | 1978-08-08 | Fibre optic tap |
FR7919670A FR2433190A1 (en) | 1978-08-08 | 1979-07-31 | BYPASS DEVICE FOR OPTICAL FIBER |
IT7924788A IT7924788A0 (en) | 1978-08-08 | 1979-07-31 | IMPROVEMENTS IN/OR RELATED FIBER OPTIC DEVICES. |
NL7905912A NL7905912A (en) | 1978-08-08 | 1979-08-01 | FIBER OPTIC DEVICE. |
AU49495/79A AU4949579A (en) | 1978-08-08 | 1979-08-02 | An optical fibre tap |
DE19792931530 DE2931530A1 (en) | 1978-08-08 | 1979-08-03 | ARRANGEMENT FOR UNCOUPLING LIGHT FROM A LIGHT-FIBER-TRANSFER LINE |
JP10034579A JPS5525098A (en) | 1978-08-08 | 1979-08-08 | Tapping device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB7832525A GB2027546A (en) | 1978-08-08 | 1978-08-08 | Fibre optic tap |
Publications (1)
Publication Number | Publication Date |
---|---|
GB2027546A true GB2027546A (en) | 1980-02-20 |
Family
ID=10498906
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB7832525A Withdrawn GB2027546A (en) | 1978-08-08 | 1978-08-08 | Fibre optic tap |
Country Status (7)
Country | Link |
---|---|
JP (1) | JPS5525098A (en) |
AU (1) | AU4949579A (en) |
DE (1) | DE2931530A1 (en) |
FR (1) | FR2433190A1 (en) |
GB (1) | GB2027546A (en) |
IT (1) | IT7924788A0 (en) |
NL (1) | NL7905912A (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2119121A (en) * | 1982-04-29 | 1983-11-09 | Western Electric Co | Optical coupling devices |
GB2144557A (en) * | 1983-07-08 | 1985-03-06 | Int Standard Electric Corp | Optical coupler |
US4826274A (en) * | 1986-12-24 | 1989-05-02 | Motorola, Inc. | Optical coupling arrangements including emitter and detector placed inside of a hollow closed end reflective waveguide |
EP1298467A1 (en) * | 2001-09-10 | 2003-04-02 | JDS Uniphase, Inc | Optical wavelength selective switch without distortion of unblocked channels |
WO2004044634A1 (en) * | 2002-11-13 | 2004-05-27 | Battelle Memorial Institute | Optical wavelength division mux/demux with integrated optical amplifier |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3029135A1 (en) * | 1980-07-31 | 1982-02-25 | Siemens AG, 1000 Berlin und 8000 München | IN / OUT COUPLING ELEMENT FOR IN / OUT COUPLING LIGHT POWER IN / FROM AN OPTICAL WAVE GUIDE CONSTRUCTING WAVE GUIDE CORE AND SHEATH AND METHOD FOR PRODUCING THIS IN / OUT COUPLING ELEMENT |
JPS59158746A (en) * | 1983-02-28 | 1984-09-08 | Toshiba Corp | Paper feeder |
WO1988009944A2 (en) * | 1987-06-03 | 1988-12-15 | Hughes Aircraft Company | Fiber optic bimodal receiver |
-
1978
- 1978-08-08 GB GB7832525A patent/GB2027546A/en not_active Withdrawn
-
1979
- 1979-07-31 IT IT7924788A patent/IT7924788A0/en unknown
- 1979-07-31 FR FR7919670A patent/FR2433190A1/en active Pending
- 1979-08-01 NL NL7905912A patent/NL7905912A/en not_active Application Discontinuation
- 1979-08-02 AU AU49495/79A patent/AU4949579A/en not_active Abandoned
- 1979-08-03 DE DE19792931530 patent/DE2931530A1/en not_active Withdrawn
- 1979-08-08 JP JP10034579A patent/JPS5525098A/en active Pending
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2119121A (en) * | 1982-04-29 | 1983-11-09 | Western Electric Co | Optical coupling devices |
GB2144557A (en) * | 1983-07-08 | 1985-03-06 | Int Standard Electric Corp | Optical coupler |
US4826274A (en) * | 1986-12-24 | 1989-05-02 | Motorola, Inc. | Optical coupling arrangements including emitter and detector placed inside of a hollow closed end reflective waveguide |
EP1298467A1 (en) * | 2001-09-10 | 2003-04-02 | JDS Uniphase, Inc | Optical wavelength selective switch without distortion of unblocked channels |
US7014326B2 (en) | 2001-09-10 | 2006-03-21 | Jds Uniphase Corporation | Wavelength blocker |
WO2004044634A1 (en) * | 2002-11-13 | 2004-05-27 | Battelle Memorial Institute | Optical wavelength division mux/demux with integrated optical amplifier |
US7155085B2 (en) | 2002-11-13 | 2006-12-26 | Battelle Memorial Institute | Amplifying wavelength division mux/demux |
Also Published As
Publication number | Publication date |
---|---|
AU4949579A (en) | 1980-02-14 |
DE2931530A1 (en) | 1980-02-28 |
JPS5525098A (en) | 1980-02-22 |
IT7924788A0 (en) | 1979-07-31 |
FR2433190A1 (en) | 1980-03-07 |
NL7905912A (en) | 1980-02-12 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4815807A (en) | Collimator lens for optical fiber | |
US3832028A (en) | Coupler for optical waveguide light source | |
US3779628A (en) | Optical waveguide light source coupler | |
US4381882A (en) | Fibre optic termination | |
US4253727A (en) | Optical coupler for optical fibres | |
JP5478888B2 (en) | Transceiver consisting of a single aperture, multiple optical waveguide | |
US5604587A (en) | Long capillary waveguide raman cell | |
US4060308A (en) | Angle selective coupler for optical fibers | |
US3756688A (en) | Metallized coupler for optical waveguide light source | |
US5457759A (en) | Monolithic optical system and method of making same including improved coupling means between an optical fiber and a phototransducer | |
US5699464A (en) | Lens structure for focusing the light emitted by a multimode fiber | |
US3780295A (en) | Light source coupler for optical waveguide | |
US7920763B1 (en) | Mode field expanded fiber collimator | |
US6349159B1 (en) | Lenses that launch high bandwidth modes into a fiber optic cable while eliminating feedback to a laser | |
US3937560A (en) | Single fiber access coupler | |
US4600267A (en) | Optical distributor | |
GB2031182A (en) | Optical waveguid arrangements | |
GB2027546A (en) | Fibre optic tap | |
KR900007290B1 (en) | System and method for detecting a plurality of targets | |
US4149770A (en) | Single-fiber duplex coupler | |
Benner et al. | Low-reflectivity in-line variable attenuator utilizing optical fiber tapers | |
JPS61158306A (en) | Numerical aperture convertor | |
US4995694A (en) | Fiber optical beam splitting device | |
US4747651A (en) | Three-way start splitter for optical wave guides | |
Powell | Application of optical fibres to astronomical instrumentation |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |